小麦对土壤铬富集和转运的品种差异性研究

Wheat cultivar difference in bioconcentration and translocation of chromium in soil

为了筛选铬(Cr)的低累积小麦品种从而为农产品安全生产提供依据,本文通过生物试验研究了小麦对土壤Cr富集和转运的品种差异性。设置0(CK)、5.6 mg·kg^(-1)(T1)和10.0 mg·kg^(-1)(T2)3个浓度的Cr(Ⅵ)处理,采用温室盆栽试验研究山东潮土和江西红壤中12个品种的小麦对土壤Cr的富集和转运规律。结果表明:在Cr(Ⅵ)处理浓度相同的情况下,同一品种小麦秸秆和籽粒Cr含量在两种土壤之间存在显著差异(P<0.05),山东潮土中的小麦籽粒Cr含量是江西红壤中的1.07~2.50倍。山东潮土中,不同品种小麦秸秆Cr含量在T1和T2处理下均无显著差异,籽粒Cr含量在T2处理下除轮选988和百农AK58外,其他品种间均有显著差异(P<0.05);江西红壤中,小麦秸秆Cr含量仅在扬麦20和轮选988中有显著差异(P<0.05),籽粒Cr含量在不同品种间无显著差异。T1和T2处理下,山东潮土和江西红壤中12个品种小麦的生物富集系数(小麦Cr含量与土壤有效态Cr浓度的比值)分别为0.19~1.38和0.18~2.08,Cr从秸秆到籽粒的转运系数(TF)分别为0.14~0.61和0.04~0.49。研究发现,小麦籽粒Cr含量和TF值呈显著正相关(P<0.05),土壤性质对小麦籽粒Cr含量影响的贡献率最大(P<0.001),山东潮土中有效态Cr浓度更高,对小麦的生物有效性更大。研究结果表明,山农17是Cr的低累积小麦品种,百农AK58是Cr的高累积小麦品种。

Screening of wheat cultivars with low chromium(Cr)accumulation as a basis for the safe agricultural products and elucidating the differences of wheat cultivars in bioconcentrating and translocating soil Cr were carried out through biological experiments. In this study, Shandong fluvo-aquic soil and Jiangxi red soil were spiked with three concentrations of Cr(Ⅵ):0(CK), 5.6(T1), and 10.0 mg·kg^(-1)(T2). A greenhouse pot experiment was conducted to investigate the bioconcentration and translocation of Cr by growing 12 wheat cultivars in the two different soils. The results showed that at the same concentration of Cr(Ⅵ), the Cr contents recorded in the wheat straw and grain of the same wheat cultivar were significantly different between the two soils(P<0.05). The Cr contents in the grains of wheat planted in Shandong fluvo-aquic soil were 1.07 to 2.50 times higher than that in Jiangxi red soil. No significant difference was observed in wheat straw Cr content among different wheat cultivars planted in Shandong fluvo-aquic soil under T1 and T2 treatments, whereas there was a significant difference(P<0.05)in grain Cr content among the cultivars under T2 treatment except for Lunxuan 988 and Bainong AK58. In Jiangxi red soil, significant differences in wheat straw Cr content(P<0.05)were observed between Yangmai 20 and Lunxuan 988, and there was no significant difference in grain Cr content among the different cultivars. Under T1 and T2 treatments, the bioconcentration factors(the ratio of Cr content in wheat to available Cr concentration in soil)of the 12 wheat cultivars in Shandong fluvo-aquic soil and Jiangxi red soil were 0.19~1.38 and 0.18~2.08, respectively. The translocation factors(TF)of Cr from straw to grain were 0.14~0.61 and 0.04~0.49, respectively. There was a positive correlation between the wheat grain Cr content and TF value(P<0.05). Moreover, soil properties contributed the most to the wheat grain Cr content(P<0.001). The available Cr concentration in Shandong fluvo-aquic soil was higher, and thus, the bioavailability to wheat plants was increased. The Shannong 17 variety had a low accumulation of Cr, while Bainong AK58 variety had a high accumulation of Cr.